I am working on putting rear disc brakes on my car right now, tonight I went to remove the axles and found that my retaining bolt for the pinion shaft in the rear diff, was sheared off. after alot of drilling and beating with a maul, (and even more cursing) I got it out. But in order to get the broken parts out, I ended up drilling two small holes in the carrier itself. one being 1/4 inch and the other about 1/8, you think by haveing these holes in the carrier, it will throw it off balance and give me alot of rear end vibration? I am dreading the idea of buying a new carrier and going threw all the work that goes with it.